High temperature resistant fan



April 3, 1934. D. P. OGDEN HIGH TEMPERATURE RESISTANT FAN Filed Dec. 17,1929 3 Sheets-Sheet 1 A ril 3, 1934. D. P. OGDEN 1,953,540

HIGH TEMPERATURE RESISTANT FAN Filed Dec. 17, 1929 3 Sheets-Sheet 2ZiZwiZZ/7i' M 17mm? (Mm, WM MW D. P. OGDEN 1,953,540

HIGH TEMPERATURE RESISTANT FAN Filed Dec. 17, 1929 3 Sheets-Sheet 3April 3, 1934.

W ir 1 Q 3 134 T t rllvlll NW1: m m A a \RL/ Patented Apr. 3, 1934UNITED STA'PS PATENT ()FFICE Dana ll. Ogden, Ottawa, 111., assignor ofone-half to Ermin F. Plumb, Streator, Ill.

Application December 1'7, 1929, Serial No. 414,641

6 Claims.

This invention relates to fans particularly designed for use inconnection with highly heated gases, such, for example, as are producedin kilns for the drying and firing of bricks or other ceramic material,or in other apparatus for heat treating where gases up to, say, about2000 F. come directly in contact with fan parts. In order to Withstandsuch high temperatures, the fan parts with which the hot gases contact,must be made of high temperature-resistant material, and. for therotating parts, heat-resistant alloys, such as those compounded largelyof chromium and nickel, are most suitable. For somewhat lowertemperatures specially treated iron or steel may be employed, such, forexample, as the so called calorized iron, which has been packed inaluminum dust and heated for a considerable time. This calorized ironmay be used for temperatures up to l,4.00 to 1,600 F. The hightemperatureresistant alloys usually contain between and 35% chromium, aconsiderable proportion of nickel and some iron. A small carbon contentaids in machining of this material. One alloy suitable for the highertemperatures, for example, comprises chromium, 30%; nickel and iron 55%.It is usually impracticable to attempt to roll such alloys into sheetform and accordingly the fan of this invention is designed to be formedu from cast metal and assembled with a driving shaft with the necessityof only little and simple machining.

' Provision is also made by which the rotating parts may be balanced forsmooth running. Special means may also be provided for air cooling thefan shaft which also preferably is composed of the alloy or of thespecially treated iron. The scrolls in which the rotating blades arepositioned are also preferably built up from preformed units, either ofhigh resistant metal or fire brick, since standard masonry, plastic firebrick, and other usual furnace construction materials are usuallyunsatisfactory in that pieces are liable to break 01f under the extremeconditions of use and fall into and wreck the rotating fan.

Improved. means for closing off thescrolls through which the fans areinserted and removed, alsoform part of this invention.

Fora more complete understanding of this invention, reference may be hadto the accompanying drawings in which Figure 1 is a view partly in sideelevation and partly in vertical section through the fan, a part oi thescroll being omitted.

Figure 2 is a. perspective of a portion of the fan shaft.

Figure 3 is a side elevation of a securing bolt for the lining of thescroll plug.

Figure 3a is a detail section on line Bot-3a of Figure 3.

Figures l, 5 and 6 are sections on the correspondingly marked sectionlines of Figure 1.

Figure '7 shows in perspective a manner in which the fan blades areassembled on the fan shaft.

Figure 8 is a view similar to a portion of Figure 4, but showing amodification.

Figure 9 is a section on line 9-9 of Figure 10.

Figures 10 and 11 are sections on the correspondingly marked sectionlines of Figure 9.

Figure 12 shows in elevation a pre-formed metallic scroll.

Figure 13 is a section on line 13-43 of Figure 12.

Referring to Figure 10, at 1 is indicated a portion of a furnace orheat-treating mechanism of the continuous tunnel type through which isdesigned to be moved the material to be treated, herein shown as bricksor similar ware, as at 2, on cars which are supported on tracks (notshown) running lengthwise of the tunnel in the well known manner. Inorder that the hot gases nay be caused to circulate about the ware to betreated, fans with which the hot gases come into direct contact areprovided as shown, for example, in my Patent No. 1,768,486 granted June24, 1930, for Continuous car tunnel furnace. These fans 3 are intendedto be placed in suitable fan scrolls as shown by dotted lines in Figure10, taking the gases into contact therewith substantially centrally andby centrifugal force causes these gases to pass out from the fan scrollas through the ports 4.

Figures 1 to 6 show the preferred fan construction which forms a portionof the subject matter of this invention. Referring to Figure 1, it willbe noted that the fan scroll is provided with an opening 5 on its outerface which is normally closed by a plug 6. This plug, as shown, is madeof suitable material such as reinforced concrete and in order that itmay be protected from the high temperatures of the gases which arepassed through the scroll, its inner face is shown as surfaced by aplate 7 of high temperature-resistant material such as the chromiumalloys hereinb'efore mentioned where temperatures up to, say, 2,000Fahrenheit are to be handled, or specially treated iron, such as theso-called oalorized iron, where gases of temperatures up to 1400* to1600 only are to be handled. As shown this plate is fixed by means ofspecially constructed bolts 3 to the inner face of the plug 6 andagainst a refractory cement layer 9 in which spaced por tions 10 of thebolts 8 are embedded. Portions 11 of this refractory cement extendingbetween the portions 10 of the bolts hold the bolts securely againstrotation or removal. These bolts 8 are provided with conical heads 12for engagement in mating openings in the plate '7 and are preferablymade of the high temperature-resistant alloy or specially treated iron.Their outer ends pass through a sectional sheet metal facing 15 on theoutside of the plug 6 where nuts 16 are engaged therewith. These nuts 16may also secure in position retaining rings 1'7, which act to hold aheat-resistant packing material such as asbestos at 18 over a centralopening 19 through which extends a fan shaft 20. The facing plate 15 maybe secured as by means of angle brackets 200 and suitable bolts on afacing 21 to the outside of the scroll. Suitable handles 25 may besecured to the facing plate 15 to facilitate removal of the plug fromthe fan scroll as when it is desired to remove the fan therefrom. Thefan shaft 20 is shown as supported for rotation by a pair of bearings atand 31, both of which are positioned outside of the fan scroll. Theouter bearing 30 is shown as a ball bearing of the usual type out wardlyof which the shaft 29 is provided with any suitable form of coupling, asat 32, for connection to a suitable driving source as the armature shaft33 of a motor 34. The inner bearing 31 is shown as positioned exteriorlyof a wheel rim spaced by spokes 41 from a hub 42 having a centrallytapered opening engaging a mating tapered outer face of the shaft 20.This shaft 20, which extends through the plug 6, is filled withheat-resistant packing material in the inner portion which is exposed tothe highest temperatures, being preferably filled with some suchmaterial as kieselguhr at 59 and the outer portion being filled withmaterial such as asbestos as at 51. This packing material is heldbetween the inner edge of the fan blades 52 and a suitable plug 53.outwardly of the plug 53 the shaft 20 is shown as tapered and is leftunfilled, having a hollow interior as 55 with which communicate openings56 through the shaft wall. When the shaft is stationary and is at anelevated temperature, these openings cause a natural upward draft of airwhich tends to cool the shaft. When the shaft is rotating a current ofair may be forcibly drawn through this portion of the shaft and for thispurpose inwardly of the bearing 31 it is shown as provided with aplurality of fan blades 65. As shown best in Figure 2, the outer edgesof these lades which extend to the inner edge of the hub 42 are rivetedbetween end flanges 61 of a circular series of segmental plates 62surrounding the shaft. These plates 62 act not only to fix the blades inposition, but also shield the outer portions of the shaft against heatpassing by the packing 18 and act to confine the air set in motion bythe fan to that coming through the outer portion of the shaft andpassing between the spokes 11 of the inner bearing wheel. Thus duringthe rotation of the fan there is set up a positive air draft which tendsto cool the shaft.

The manner of assembling the blades with the fan shaft is shown best inFigure 7. These blades are preferably cast, particularly when made ofhigh temperature-resistant alloy, since it is very difficult if notimpossible to satisfactorily produce roll shapes of this material. Theinner end of the shaft 20 is machined on its inner face and is providedwith a plurality of slots extending back from its inner end. Each of thefan plates as 52 has at its inner end a segmental bead 72 which fitsagainst the inner wall of the shaft 70 when the adjacent portion of theblade is placed within a slot '70 in the position shown in Figure 4.These beads 72 of the several blades together substantially fill thecircumferential space closely adjacent to the inner wall of the shaft sothat each plate supports its adjacent plates against moving inwardly.The blades may be further secured in position by driving tapered keys 73through openings 74; therein positioned so that the keys engage againstthe outer face of the shaft portions '75 between the slots 70. Ifdesired the fan blades may be cast together in one piece, beingcentrally joined by a hub portion (see Figure 8) which is shaped toengage within the shaft 20, the blades projecting outwardly through theslots 70. As shown each blade is provided with a slot therethroughextending outwardly from its inner edge. Through this slot may bepositioned U shaped pieces 86 which may be secured over the outer edgesof the slots 85 and engage in opposite sides of the blade as by rivets8'7. By a proper selection of the weight of these U shaped membersinequalities in the weights of the several blades of a fan may becompensated for so that the fan when completed may be in substantialrotative balance. This is of particular importance where fans havingvanes of substantial weight such as cast metal are employed and alsowhere they are subjected to the severe operating conditions occasionedby direct contact therewith of the hot gases. The fan blades may befurther secured in position on the shaft by internal and externalcollars 90 and 91 secured to the shaft at either side thereof as shownin Figure 1. It will be noted that the entire bearing support for thefan is positioned outside of the scroll and in order that the fanassembly may be removed as a unit from the scroll readily through theopening 5, the bearings and driving motor are shown as supported on asingle bed 99 outside of the furnace, which bed can be unbolted andpulled rearwardly as desired, preferably cushioning material beingpositioned beneath the bolts as at 100 to absorb vibration. Thisassembly of the fan blades and shaft is not claimed herein but forms thesubject matter of divisional application Serial No. 529,733 filed April13, 1931, now Patent No. 1,999,885 granted May 16, 1933 for Fan.

The scrolls within which the fans are designed to operate are preferablyformed of pre-molded units interlocking with each other as the usualmasonry building materials are liable to break down in service, fallinginto the fan and causing damage thereto. These fan scrolls may be madeof pro-formed masonry units, each shaped in accordance with its place inthe scroll and preferably interengaging as through grooves 101 andprojections 102 in mating elements 103 as illustrated in Figures 9 and10. Space may be economized where this is desirable by forming thescroll in pre-formed units of the high temperature-resistant alloy.Where this is done the units may be cast, mating units being formed tointerengage each other. As shown, for example, in Figure 13 each unit as120 may be provided with a tongue portion 121 engageable through anopening 122 in a mating unit and held in position in that unit as bymeans of a key 123 inserted through an opening in its projection andengaging the face of the mating unit. This scroll construction is alsonot claimed herein but forms subject matter of a divisional applicationSerial No. 529,734 filed April 13, 1931 for Fan scroll.

From the foregoing description of certain embodiments of this invention,it should be evident to those skilled in the art that various changesand modifications might be made without departing from the spirit orscope of this invention as defined by the appended claims.

I claim:

1. A mechanism of the class described comprising a fan scroll, a fan insaid scroll, a shaft for said fan extending outwardly of said scroll,means outwardly of said scroll for rotating said shaft, said shaftextension being hollow, and means outside of said scroll for causing airto pass through said hollow extension to cool the same.

2. A mechanism of the class described comprising a fan scroll, a fan insaid scroll, a shaft for said fan extending outwardly of said scroll,means outwardly of said scroll for rotating said shaft, said shaftextension being hollow and unobstructed and having lateral openingsleading from said hollow portion, and means outside of said scroll fordrawing air through said lateral openings and through said shaft.

3. A mechanism of the class described comprising a fan scroll, a fan insaid scroll, a shaft for said fan extending outwardly of said scroll,said shaft extension being hollow and having lateral openings leadingfrom said hollow portion,

means outwardly of said scroll for rotating said shaft, and fan bladeson said shaft outside of said scroll for drawing air through said hollowshaft and openings when said shaft is being rotated.

4. A mechanism of the class described comprising a hightemperature-resistant fan scroll having an opening, a removable plug forclosing said opening, a fan of high temperature-resistant material insaid scroll, a hollow shaft for said fan extending through said plug,high temperature-resistant material in the hollow of said shaft withinsaid plug, means independent of said fan for cooling said shaftoutwardly of said plug, and means coupled to said cooled portion forrotating said shaft.

5. A mechanism of the class described comprising a fan scroll, a fan insaid scroll, a shaft for said fan extending outwardly of said scroll,means outwardly of said scroll for rotating said shaft, said shaftextension being hollow, and. means for drawing air through saidextension and discharging it outside of said scroll.

6. A mechanism of the class described comprising a fan scroll, a fan insaid scroll, a shaft for said fan extending outwardly of said scroll,means outwardly of said scroll for rotating said shaft, said shaft beinghollow, a non-heat conducting packing in the hollow of said shaftadjacent to said fan, and means for drawing air through the hollow ofsaid extension and discharging it outwardly of said scroll.

DANA P. OGDEN.

